A massacumber is a subterranean plant, similar in appearance to an enormous potato or other tuber. It reproduces by asexual budding, and can spread throughout an area rapidly. They are capable of drawing nutrients from the soil, but supplement themselves with creatures. Although they can move, it is a slow burrowing. They can typically be found resting just a few inches below the surface.

Combat Massacumbers attack any Small to Large creature that comes within striking range. Their tentacles have barbed tips and can be quite difficult to remove. Once a tentacle is hooked into its prey, it begins to secrete a digestive fluid into the prey. After the prey is killed, the massacumber burrows underneath to feed. The tentacles can be severed by a single slashing attack that deals one fourth of the massacumber's original total hit points. Any excess damage is lost. The massacumber can not make any attacks with a severed tentacle, but suffers no other penalties. A severed tentacle regrows in several weeks. If a massacumber loses two or more of its tentacles, it usually retreats by digging deeper into the ground, where its opponents can not reach without digging after it.Due to the massacumber being buried in the soil, its body has full cover, unless it is attacking, in which case it has nine-tenths cover. The tentacles use the listed AC when in combat.

Harpoon Strike (Ex): The massacumber's tentacles end in barbed tips that dig deep into the flesh of its prey. Any creature struck by a tentacle must make a Reflex save (DC 10+damage taken) or the tentacle becomes lodged in its flesh. A hooked creature moves at only half speed and can not charge or run. The creature's movement can be controlled by the massacumber with an opposed Strength check. The tentacle can be removed by the creature, or ally, if it has two free grasping limbs, and takes a full round to do so. Removing a tentacle inflicts damage to the creature equal to the initial damage. Any hooked creature that attempts to cast a spell, it must succeed at a Concentration check (DC 15) or fail, losing the spell.

Digestive Acid (Ex): One round after hooking a creature, the tentacles begin secreting a digestive acid into the opponent. Each tentacle deals 1d2 temporary Con damage per round that it remains hooked to the creature.

Tremorsense (Ex): The massacumber can automatically sense the location of anything within 60 ft that is in contact with the ground. This is the massacumber's only mean of sensing prey.

Physical Link (Ex): A massacumber extends numerous filaments throughout the soil around it. These filaments bind to the filaments of other massacumbers, creating a physical connection between all massacumbers within an area. Massacumbers within 50 ft of each other are connected. This connection can only be broken by completely removing the massacumber from the ground and cutting the filaments. The filaments will regrow if broken.

Shared Senses (Ex): Any linked massacumbers can sense through another massacumber's tremorsense. Once one massacumber senses prey, others in the area typically respond, and move towards the prey. If the massacumber's physical link is broken, it can not use this ability.

Shared Health (Ex): Any massacumbers that are connected share hit point damage inflicted on the main body equally. The damage is shared among massacumbers closest to the one attacked first. If the massacumber's physical link is broken, it can not use this ability.

Shared Strength (Ex): A massacumber gains a +2 to its Strength for every additional linked massacumber. If a massacumber's physical link is broken, it can not use this ability.